1. Field of the Invention
This invention relates to glass handling apparatus for handling large panes of flat glass, and particularly to an apparatus that may be used to separate a single or a selected number of panes from a larger number of panes making up a "block" of glass panes.
2. Description of the Prior Art
A search of the prior art has revealed the existence of the following U.S. Pat. Nos. 1,621,650; 2,801,876; 2,828,870; 3,838,779; 3,909,056; 3,913,965; and 4,489,970. Only three of these patents relate to glass handling apparatus, and none of these three disclose the invention described herein.
It is not generally known that flat panes of glass, such as glass commonly known as "float" glass, is manufactured in large flat sheets or panes ranging between 168" to 240" long and ranging from 128" to 130" wide. Panes of glass in these large sizes are conventionally paced side-by-side in contiguous juxtaposition to form a "pak" or "block" of glass panes. These "paks" or "blocks" weigh either 5,000 pounds or about 10,000 pounds, and have thicknesses from 2" to 4". One reason that glass manufacturers store the glass panes in 5,000 and 10,000 pound paks is that end users (the manufacturer's customers who cut the large sheets into smaller glass panes) are generally equipped with maximum hoisting capacity that varies from 5,000 to 10,000 pounds. But this arrangement requires that 5,000 pound paks be stored separately from 10,000 pound paks in the manufacturer's warehouse, i.e., in a different area, and that each pak be separated from the next adjacent pak by blocking that creates a 2" to 3" space between adjacent paks. This space is required to permit encirclement of the ends of the pak by nylon slings that are conventionally used to lift paks of glass. Such blocking takes up valuable floor space, e.g. up to 50% of the total storage floor area is taken up by these "spaces" between each pak.
It will thus be understood that conventional storage practices for flat float glass is wasteful of floor space, which could be used to great advantage in storing more glass in a given floor area.
The reason conventional glass handling practices require the arrangement of the glass in paks constituted of a limited number of panes is that conventional glass handling apparatus must hoist the entire pak as a unit to prevent shattering of the brittle and fragile glass panes. Since a pak 2" thick containing eight panes of 1/4" thick float glass (of the size 130".times.204") weighs about 5,000 pounds, it is readily understood that the type and capacity of the hoisting equipment used by the customers is one of the factors that dictates the conventional practice of storing glass in 5,000 pound and 10,000 pound paks at the manufacturer's plant.
Another reason that "loose" glass, i.e., uncased glass, has not heretofore been stored in a solid "block" of indefinite thickness is that heretofore the glass manufacturers have lacked the mechanical equipment that would enable them to stack 5,000 pound and 10,000 pound paks in contiguous juxtaposition, and have likewise lacked the mechanical equipment that would enable them to retrieve from such a solid "block" of glass a predetermined number of panes of glass to make up a 5,000 or 10,000 pound pak for shipment to a customer.
Accordingly, it is one of the objects of my invention to provide a glass handling apparatus that is capable of stacking and retrieving a predetermined multiplicity of panes of glass to or from a solid "block" of indefinite thickness of such glass panes that are stored on edge in a nearly vertical attitude.
Another object of the invention is the provision of a glass handling apparatus that is also capable of retrieving a single pane of glass from a "solid" block of such glass panes, and transporting such glass pane to another location.
Glass handling equipment heretofore used to retrieve glass paks from storage conventionally require three workers to engage the lifting equipment (nylon slings) to the glass paks--one on the hoist and one at each end of the pak to engage the nylon lifting slings to both ends of the glass pak. A still further object of the invention is the provision of a glass handling apparatus that engages the glass pak automatically, eliminating the need for attaching nylon slings to both ends of the pak and which may be operated by a single person, thus saving the labor expense usually incurred through use of conventional glass handling methods, including the need for workmen to stand by as the glass pak is about to be lifted to make sure that the nylon slings are properly engaged to the glass pak before lifting commences.
A still further object of the invention is the provision of a glass handling apparatus equipped with gauge means that may be pre-set to select a predetermined number of panes of glass from a solid "block" of such glass panes.
The invention possesses other objects and features of advantage, some of which, with the foregoing, will be apparent from the following description and the drawings. It is to be understood however that the invention is not limited to the embodiment illustrated and described, since it may be embodied in various forms within the scope of the appended claims.